Spark chamber for automatic cut-outs



Dec. 7, 1937. w. LEYHAUSEN SPARK CHAMBER FOR AUTOMATIC CUT-OUTS 2 Sheets-Sheet 1 Filed May 2, 1936 .F'J'gi Fig. 2

Dec. 7, 1937. w, LEYHAUSEN 2,101,783

SPARK CHAMBER FOR AUTOMATIC CUT-OUTS Fild May 2, 1936 2 Sheets-Sheet 2 I I 1; 0 1* 0, i .i: .r "F. i I; I --+F1g.3

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Patented Dec. 7, 1937 SPARK CHAMBER FOR AUTOMATIC CUT-OUTS Wilhelm Leyhausen, Nuremberg, Germany Application May 2, 1936, Serial No. 77,587 In Germany May 3, 1935 4 Claims.

This invention relates to a sparking chamber for overload circuit breakers and has special reference to a chamber of this character having an electro-magnetic blow-out for the are produced by sparking when a circuit is opened.

One important object of the invention is to provide a novel arrangement of such a chamber wherein means age supplied for admission of air to the sparking c amber to overcome the vacuum effect produced in a closed chamber by the sparking therein whereby cooling of the contacts is eflected and ionization of the air in the chamber is eliminated.

A second important object of the invention is to arrange the contacts of an overload circuit breaker in a narrow chamber having a blow-out magnet at each side thereof whereby highly effective blow-out effects are produced.

A third important object of the invention is to so shape the chamber that the arc field is surrounded on all sides by closed walls, thus preventing injurious efiects outside of the chamber, the latter being provided with air ports so offset as to prevent escape of the arctherethrough.

With the foregoing and other objects in view, the invention consists in the details of construction, and in the arrangement and combination of parts to be hereinafter more fully set forth and claimed.

In describing the invention in detail, reference will be had to the accompanying drawings forming part of this application, wherein like characters denote corresponding parts in the several views. and in which- Fig. 1 is a section on the line II of Fig. 2;

Fig. 2 is a section on the line II-II of Fig. 1;

Fig. 3 is a section on the line III-III of Fig. 4;

Fig. 4 is a section on the line IV-IV of Fig. 3.

Fig. 5 is a perspective view of an inserted wall member made in one piece.

In the form of the invention according to Fig. 1 the construction is as follows:

Upon the base s (Fig. 1) are spring supported contacts a and b. A contact bridge member c is disposed opposite to them. Said contacts a and b and said contactbridge member 0 are encased by the spark chamber I. At the sides of the spark chamber f magnet coils m and m are arranged (Fig. 2). An air-inlet tube i is provided between the contacts a and b. The passage openings provided in the bottom of the spark chamber for the contacts a and b are of sufficiently large dimensions, so that the air can enter around them from below.

In Fig. 1 the contacts are shown during the .of contact.

disconnecting action. The contact bridge member c previously has been spanning the contacts a and b and has just been moved upwards out Thus, the arcs o and 0' are produced which are blown outwards by the magnetic field. 5 Owing to the partial vacuum thereby caused, fresh air flows through the bore is formed in the socket, or base s as well as past the contacts a and b through the channels 1' and 25 provided in the underside of the spark chamber. The air then 10 flows through the bore i into the blow center and is driven outwards with the are at the switch. In order to obtain a cooling down of the gases flowing out of the spark chamber, partition walls w and w are provided transversely across the 15 blow direction on the narrow sides of the spark chamber 1. The hot gases strike against these partition walls and then flow through the channels n, n, n, n into the open or into the interior of the switch respectively, where they can do no go more damage. In order to increase the action of cooling down of the gases, the partition walls w, w are larger dimensioned on the narrow sides 01' the spark chamber 1 than are the corresponding walls of the spark chamber. 5

The partition walls w, w have not only the task of stopping or deviating to cool down the arcing at the switch, but they cause also a considerable damping of the sound or noise occurring in switching out heavier short circuits. Said 30 noise propagates in the same direction as the arcing at the switch, but is repeatedly stopped and refracted by means of the tortuous passage formed by the walls w, w.

In the form of execution according to Figures 5 3 to 5, special arrangements are made for increasing the output of small cut-outs and to obtain the extinguishing of the are as quickly as possible. The spark chamber 1, as illustrated in the Figures 3 to 5, is generally constructed in the 40 same manner as that described and shown. in the Figures 1 and 2, but for the purpose of increasing the damping action, partition walls 9', g, g g are provided which are arranged at both sides of the contacts a, b. Thus, the spark chamber f is 45 divided into a plurality of spaces. Thereby the are '0, o' is choked and cooled down in such a manner that it is extinguished very quickly.

To explain the intensity with respect to the action of such a simple device the trial described 50 in the following shows the results marked by the oscillation method.

An installation of the automatic cut-out, spark chamber and magnet arrangement of the construction. described in Figs. 1 and 2, with a mag- 55 current intensity of 15 amperes) was inserted in a. direct current circuit for 250 volts, with ashort circuit current of 5000 amperes. The automatic cut-out without trouble extinguished the arc in 0.0046 second.

A similar cut-outponstructed according to Figs. 3 and 4 with partition walls g, g, g, 9 inserted and with a magnet winding of only 14 turns (corresponding to a rated current intensity of amperes within the same circuit and with a short circuit current for 10,000 amperes) extinguished the arcing at the switch in 0.0015 second. These tests show with respect to the windings of coil an output of more than twelvefold.

It is apparent from the above that the firs cut-out for 5000 amperes disconnected more than the sixfold of the current intensity required by the association of German electrical engineering.

It is necessary to consider further that it was detrimental to the output of the cut-out to provide the spark chamber with partition walls lying transversely across the direction of flow of the are.

As is shown in Figure 5, the intersected walls 9, g and g, g advantageously held by cross members h, h and h M. In such a structure, said walls can form an insert member formed in one piece. By means of this structure it is possible to turn a normal spark chamber into one for a higher output. It is, further, possible to simplify spark chambers which are to be fitted with this structure during manufacture. That is, the channels n, n, n and n in the extensions of the spark chamber at both of its narrow sides may be left out. as the resulting gases are already cooled down sufiiciently in the interior of the chamber.

The invention is obviously subject to other forms and expressions without departing from the spirit thereof or scope of the appended claims.

What I claim is:

1. In an overload circuit breaker, a base, a pair of spaced contacts spring supported from said base, a movable contact normally bridging said spaced contacts, a substantially closed chamber surrounding said contacts and resting on said base, means to admit air to said chamber between net winding of 28 turns (corresponding to a rated said pair of contacts, means at the ends of said chamber to discharge air from the chamber, and a pair of blow-out magnets supported on said base at opposite sides of the chamber and disposed in alinement with the space in the chamber centrally above the pair of contacts.

2. In an overload circuit breaker. a base, a pair of spaced contacts spring supported from said base, a movable contact normally bridging said spaced contacts. a substantially closed chamber surrounding said contacts and resting on said base, means to admit air to said chamber between said pair of contacts, means at the ends of said chamber to discharge air from the chamber, a pair of blow-out magnets supported on said base at opposite sides of the chamber and disposed in alinement with the space in the chamber centrally abovethe pair of contacts, and partition walls in said chamber extending from top to bottom of the chamber parallel to the side walls of the chamber.

3. In an overload circuit breaker, a base, a pair of spaced contacts spring supported from said base, a movable contact normally bridging said spaced contacts, a substantially closed chamber surrounding said contacts and resting on said base, means to admit air to said chamber between said pair of contacts, said chamber having laterally ofiset portions at its ends provided with air outlet ports, and a pair of blow-out magnets supported on said base at opposite sides of the chamber and disposed to lie opposite the arcing field of said contacts.

4. In an overload circuit breakena base, a pair of spaced contacts spring supported from said base, a movable contact normally bridging said spaced contacts, a substantially closed chamber surrounding said contacts and resting on said base, means to admit air to said chamber between said pair of contacts, said chamber having laterally offset portions at its ends provided with air outlet ports, a. pair of blow-out magnets supported on said base at opposite sides of the chamber and disposed to lie opposite the arcing field of said contacts, and partition walls in said chamber extending from top to bottom of the chamber parallel to the side walls of the chamber.

WILHELM LEYHAUSEN. 

